Atomic force microscopy (AFM) has been used to investigate eight different Mexican crude oils in the form of deposited films on metal substrate. Most oils had reported asphaltene deposition problems during production. Two other techniques related to hydrodynamic size determination were applied: light scattering and HPLC-SEC. According to the observed AFM surface morphology characteristics oil films were classified and grouped into distinct groups. Some had dense population of 40-200 nm particles, while others had larger discoid features and smaller particles. Light scattering analysis indicates observed particles to be organic as they disappear upon dilution with toluene. Correlation between the oil film AFM morphology and physicochemical properties of the oil did not reveal a simple relationship. Indeed, oils with similar bulk fluid properties show different morphology as films. With respect to the crude oil instability and the well-deposition problem, it was found that five of the investigated oils (unstable) with known problems of asphaltene deposition during production, contain spherical or discoid nanoparticles in the range of 35 to 500 nm. Films prepared from the stable oils possess apparent two-dimensional (2D) characteristics (spread over the substrate) without particular features. Detail of AFM analysis show that oil instability can be related to films and oils with higher density of particles, and films with larger particles. It emphasizes AFM, as a technique potentially useful for the well-deposition problem detection. HPLC-SEC data show that oils from similar geographic zones have similar fluid properties in terms of composition and hydrodynamic size distribution but on the other hand could display different AFM morphology features. The results show that AFM is a promising tool for the oil film characterization and determination of surface properties, which may leads to development of a better understanding of well-deposition and adherence.